In order to screen high-yield protease strains, a strain BJ-4 with high-yield protease was screened by casein medium and identified as Bacillus amyloliquefaciens. The enzyme production conditions of the strain were optimized by single factor and response surface optimization. The optimal enzyme production conditions were determined as glucose 0.5%, beef extract 1.5%, culture temperature 37.61℃, initial pH 6.84 and inoculation amount 1.36%. The optimized enzyme activity increased by 71.01%. Strain BJ-4 is promising in industrial applications.